This invention is especially suitable for producing fill inflated tires used in on road trucks and earth moving equipment which have historically used pneumatic tires of the tube or tubeless type. Pneumatic tires are susceptible to punctures and blowouts and must be removed and repaired when such incidents happen. Unfortunately the use of equipment is lost for a period of time necessary for making the repairs. This is costly and expensive. Tires inflated with foamed elastomeric material however, are literally deflation proof and almost indestructible from normal hazards such as bolts and nails thus eliminating or substantially reducing the period of time the equipment is not in operation.
One such tire used in such applications is filled with a foamable material called Permafoam(trademark). The Goodyear Tire and Rubber Company patented this material in U.S. Pat. No. 3,872,201 issued Mar. 18, 1975. In that patent a method of curing the foam inflated tires was disclosed, wherein, the tire was at least partially filled with the material and vulcanized in such a way that the foamable elastomeric material would expand thereby filling the entire air chamber cavity of the tire and pressing against the curing rim. In the prior art, the curing rim was also the same rim that was used on the vehicle.
The use of the vehicles rim meant that the customer had to ship rims to a manufacturing site to have Permafoam(trademark) filled tires prepared. Once the rims and tires were assembled and cured, they would then be shipped back to the customer. This meant that the customer had to have duplicate sets of rims for each vehicle. This was both costly and inefficient. But it was determined that the tires could not easily be removed from the curing rim, and therefore, the most logical approach was to cure the tire on the rim that it was intended to be used on. The present invention has an objective of enabling a Permafoam(trademark) cured tire or any foam filled tire to be cured and then subsequently removed from the rim for shipping to the customer. Another objective of the present invention is to enable storage of rimless Permafoam(trademark) tires so that they can be available at the user site. Another objective is to provide a method, which ensures that the foam is not damaged during removal of the curing rim or during insertion onto the vehicle rim.
An improved method for expanding and curing foamable elastomeric material, which is placed in the cavity of the previously molded tire, is disclosed. The method has the steps of at least partially filling the cavity of the previously molded tire with foamable elastomeric material, curing the foam filled tire and removing the cured tire from the curing rim by slipping the cured tire off a finished or coated surface on the curing rim.
Once the tire is cured, the method further comprises the step of wrapping the cured tire for storage and shipment with a protective layer. Once the tire is shipped to the customer, the method then comprises the steps of removing the protective layer attaching a coated insertion cap or an insertion cone, or a combination insertion cap and insertion cone to the wheel rim abutting the cured foam filled tire, inserting the capped or cone and wheel rim into the cured foam filled tire and pressing the insertion cap or insertion cone against the cured foam filled tire sufficient to slip the tire onto the rim.
The rim for curing the previously molded tire with foamable elastomeric material has an exterior surface; the exterior surface has a coated surface for slipping the cured tire from the rim. The coating surfaces of the rim can be selected from the group including, McLube 1711C, waterless Pam grill sprays, baked on coatings like DYN-OH-COAT 100, or Teflon-S PTFE or Teflon-S FEP.